When sending a request to a website, most devices will include codes indicating the device model in the form of the User-Agent HTTP header. However, iOS devices send a User-Agent that only contains ‘iPhone’ or ‘iPad’, rather than any details about the specific model.
For example, below are the User-Agents for a Samsung Galaxy S10 and an iPhone XS Max. Note; the 51Degrees User-Agent tester page correctly returns the Samsung model but returns a number of possible iPhone models.
Samsung Galaxy S10
Mozilla/5.0 (Linux; Android 9; SAMSUNG SM-G973F Build/PPR1.180610.011) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/9.0 Chrome/67.0.3396.87 Mobile Safari/537.36
iPhone XS Max
Mozilla/5.0 (iPhone; CPU iPhone OS 12_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/16A366
- The WebGL API can be used to get the name of the GPU the device is using.
The combination of these two pieces of information can be used to identify the individual iPhone or iPad model in most cases.
With iOS 12.2, the WebGL approach is now returning the same data across all Apple devices. For example, an iPhone X running iOS 12.1 will return ‘Apple A11 GPU’ and correctly identify the device as an iPhone X.
However, when running iOS 12.2, the same device will return ‘Apple GPU’ - the critical "A11" is missing. This prevents device detection from identifying the individual model, though either an iPhone X or iPhone XS can be determined using the screen information.
Apple’s removal of the precise GPU model prevents all device detection solutions from determining the specific device model in using this GPU model technique.
Clearly this is an intentional change from Apple. Indeed, Apple’s unwillingness for their devices to expose any information that could be used to determine the model appears to be related to an initiative to enhance privacy by preventing device fingerprinting. Given the popularity of iPhone and iPad combined with the relatively limited number of models - compared to Android - 51Degrees are unsure if the removal of GPU model information really will have an impact on privacy. Particularly given the amount of information that apps installed via the App Store are able to obtain.
51Degrees will continue to investigate additional methods for determining the individual model of iPhone or iPad. However for the time being Apple have disabled the most common method of achieving precise model granularity.